Why is Pain Under treated?

There are a number of reasons that veterinarians do not administer analgesics to dogs and cats. Some veterinarians still believe that dogs and cats do not feel pain. They may also believe that an animal that is walking and eating must not be painful. While we cannot ask them directly, behavioral changes associated with routine surgery, such as ovariohysterectomy suggest that pain may be significant. Another reason veterinarians may not aggressively treat pain could be that they have a problem assessing pain. While pain assessment is definitely difficult in animals that cannot tell us directly what they are feeling, many people would advocate that animal care providers anthropomorphize and assume pain in animals under circumstances that would be painful to humans. An additional reason some veterinarians may not provide analgesia is a lack of knowledge about the drugs available, since most veterinary school curricula have not discussed pain until the recent years. Lack of knowledge creates a fear of drugs. This can easily be overcome with reading appropriate texts and journals and attending continuing education. The cost of analgesic drugs and the need to charge the client more may also inhibit appropriate pain management.

The Biologic Role of Pain

Pain clearly plays a biological role in survival. Pain signals impending or actual tissue damage and may help an animal avoid harm. Pain may also play a protective role after significant injury, preventing movement that may cause further trauma. A short period of immobility may aid healing, but prolonged immobility may actually be detrimental to musculoskeletal and cardiopulmonary function. Neurohumoral responses secondary to pain may be beneficial for healing, but if the responses become excessive they may cause significant morbidity and mortality.

Principles of Pain Control

There are 3 main principles of pain control. First, remember that pain control is good medicine. Second, analgesia should be administered preemptively, prior to a painful stimulus. Third, an analgesia protocol should consist of a multi-modal approach, using drugs which act via different mechanism in order to provide the best possible analgesia.

The Drugs Used for Acute Pain Control

Opioids, more commonly referred to as narcotics, are the most effective analgesic drugs available. Examples of opioids commonly used in veterinary medicine are morphine, hydromorphone, fentanyl, meperidine, and codeine. Xylazine and medetomidine are two commonly used alpha-2 agonists, but should not be the first choice in providing analgesia to patients.

Xylazine and medetomidine do play a role as an adjunct to opioid analgesia. They produce a synergistic analgesic effect through their G-protein transduction at the molecular level. Other drugs that can be used as part of a multimodal approach include, microdose ketamine, local anesthetics, and nonsteroidal anti-inflammatory drugs.